Generally, 3-hydroxytetrahydrofuran is useful as a chemical intermediate in the preparation of medicines and agricultural chemicals. Conventional techniques for preparing 3-hydroxytetrahydrofuran from 1,2,4-butanetriol are as follows.
In J. Org. Chem. 1983. Vol 48, 2767-2769 by Vishnu K. Tandon, a method of preparing (S)-3-hydroxytetrahydrofuran and (R)-3-hydroxytetrahydrofuran from (S)-1,2,4-butanetriol and (R)-1,2,4-butanetriol through cyclodehydration in the presence of para-toluenesulfonic acid as a catalyst was disclosed, the yield of the product being merely 87%.
U.S. Pat. No. 4,539,415 discloses a method of preparing racemic 3-hydroxytetrahydrofuran at a high yield through cyclodehydration in the presence of a fuller's earth catalyst. Although this method is suitable for the preparation of racemic 3-hydroxytetrahydrofuran through dehydration using a catalyst at a high temperature of 150-200° C., at which racemization may occur, it is limited in application to the process of preparing optically pure 3-hydroxytetrahydrofuran.
Therefore, the present invention aims to provide not only a method of preparing racemic 3-hydroxytetrahydrofuran at a high yield through cyclodehydration of butanetriol but also a method of preparing 3-hydroxytetrahydrofuran having high optical purity by maintaining the optical purity of butanetriol upon cyclodehydration.